The present invention relates to a system used to analyze compositions to determine what chemical elements are present therein and, more particularly, to a system that analyzes an air sample and, if undesired chemical warfare vapors are present therein, provides signals to activate alarms.
The ambient by which one is surrounded is of utmost importance. However, the ambient may suffer from pollution that allows the surrounding atmosphere to be contaminated, especially by man-made waste and vapor pollutants.
The environment by which one is surrounded may also be invaded by more serious pollutants, especially during terrorist situations or during warfare, in particular, chemical warfare. Chemical warfare involves the use of chemicals, such as blister and nerve gases, that attack humans and animals, with the human suffering severe bodily pain and/or death within minutes of exposure.
Current state of the art portable chemical warfare agent detectors have not demonstrated the capability to function properly on board ship due, in part, to the presence of electromagnetic interference (EMI) and non-chemical warfare (CW) agent vapors which act as interferents. These interferent vapors tend to cause false positive alarms or impede the detection and identification of the chemical warfare vapor.
Systems for measuring samples to determine the contents thereof are known and some of which may employ ion mobility spectrometers (IMSs), such as described in U.S. Pat. No. 4,445,038; 5,083,019; 5,300,773; 5,491,337; and 5,587,581, and all of which are herein incorporated by reference. The IMS provides a quantitative measurement of the contents of the molecules being sampled by measuring a time of xe2x80x9cflightxe2x80x9d of the ions of the molecules through a drift region of the IMS which is determined by the ion mobility characteristic of the ions being sampled and which, in turn, provides the identity and the concentration of the composition being measured. Accordingly, it is desired that means be provided employing ion mobility spectroscopy technology that analyzes the environment to detect the presence of unwanted chemical warfare agent vapors and provide alarm thereto, but without alarming to common interferents and EMI found in a shipboard environment. More particularly, it is desired that an Ion Mobility Spectrometer (IMS) be provided that yields a quick and improved accurate determination of these unwanted chemical warfare agent vapors so that the environment may be quickly purged thereof.
It is a primary object of the present invention to provide a system utilizing an IMS that accurately detects and monitors for the presence of undesired chemical warfare agent vapors in an environment. It is also equally important for the system not to alarm in an environment when specific chemical warfare agent vapors are not present.
It is another object of the present invention to provide a system employing an IMS that quickly, yet accurately, detects and monitors for the presence of undesired chemical warfare vapors in an environment and, upon detection thereof, provides an alarm indication.
Another object of the present invention is to provide a system having at least a first and second configuration so that an alarm condition is only generated if there is an agreement between the detection derived separately from the first and second configurations.
In addition, it is an object of the present invention to provide a system employing first and second IMSs to advantageously detect ions having both predominately positive and negative polarities, respectively, so as to simultaneously detect separate gaseous samples having respective positive and negative charge characteristics.
It is another object of the present invention to provide for an instrument that uses ion mobility spectroscopy technology that analyzes molecules of chemical agent vapors by determining the cluster arrangement of the ions making up the chemical vapor agents and conditions the molecules of selected vapors so that these molecules are more easily and accurately detected by an IMS operated to more advantageously detect ions manifesting a positive or negative charge.
Furthermore, it is an object of the present invention to provide for an IMS that generates an electrical signal which is routed to means for comparing the electrical signal against predetermined signals indicative of unwanted and/or dangerous compositions of gaseous vapors, and if a match exists therebetween, an alarm is generated.
In addition, it is an object of the present invention to provide a system that has the ability to operate on standard ship""s power or provide rechargeable means so as to operate on battery power making the system portable.
Another object of the present invention is to reduce the weight and size of the associated elements making up the system so as to further contribute to the portability of the system.
The invention is directed to a system for sampling the ambient of a selected environment for the presence of unwanted, predetermined chemical vapors therein.
The system comprises means for obtaining a sample of the selected environment and means for conditioning the sample into a vapor containing known molecules. The system further comprises means for receiving the vapor comprising ion clusters that define ions of the molecules. The means for receiving comprises first and second ion mobility spectrometers with one of the ion mobility spectrometers having arranged therewith a reagent source. The means for receiving is capable of being powered by a battery. Each of the first and second ion mobility spectrometers provides an electrical signal representative of the respectively received defined ions of the molecules. The system further comprises means for comparing each of the representative electrical signals of the first and second ion mobility spectrometers against predetermined signals representative of predetermined chemical vapors and generating an alarm signal if a match exists therebetween.